Fan having detachable blades



June 4, 1957 G. E. Mix 2,794,509

FAN mmm.; DETACHABLE BLADES Filed May A14, 1954 FAN HAVING DETACHABLEBLADES Gail E. Mix, Los Angeles, Calif.

Application May 14, 1954, Serial No. 429,752

4 Claims. (Cl. 170-173) This invention has to do with a fan havingdetachable blades and it is a general `object of the invention toprovide a fan of this type which is of simple, practical and improvedconstruction.

Fans such as are provided for the handling or circulating of air when ofappreciable size are, in many instances,

cumbersome and present difficulties in handling, as for instance, in thecourse of transporting, storing, etc. Fans of this general characterhave been heretofore provided with blades separable from hubconstructions. However, mechanisms of this type are generally rathercomplicated of construction and not altogether convenient to assemble ordependable when assembled.

It is an object of this invention to provide a fan constructioncharacterized by a hub with a holder thereon and having blades with armsreleasably secured to the holder, the whole construction being such asto involve but few simple parts and being such that the parts can beeasily and quickly assembled to be dependably and securely connectedwhen the construction is completely assembled.

Another object of this invention is to provide a structure of thegeneral character referred to including an improved hub and holderconstruction which involves few parts that are simple and inexpensiveyof manufacture and which are permanently joined or assembled to form -astructure ready for the reception of arms provided on fan blades.

Another object rof the invention is to provide a structure of thegeneral character referred to in which the fan blades are equipped witharms with projecting parts that are secured to the holder and which areprovided with stiiening portions in effect overlapping the portions ofthe holder that hold the arms and serving to render the arms rigid andhighly satisfactory. p

The fan construction provided by the invention involves a hub, tubularin form and having a reduced projection at one end, which projection hasa terminal lip portion. A holder is carried on the hub, being engagedover or on the reduced projecting portion, and it is held thereon by thelip of the hub and shaped to overlie the holder. The holder involves butthree parts, namely, two like plates and a spacer between the plates.The plates have central openings that receive the reduced portion of thehub and they have peripheral notches which divide their peripheralportions into flange-like parts that are circumferentially spaced. Theplates are assembled with their flange-like parts in register oropposed, and the spacer is between the plates separating the plates atthe central portion of the holder `or where the holder is engaged on thereduced portion of the hub. The blades are preferably alike and in apreferred form each has a main portion formed of sheet metal or thelike, and having the desired shape and form. An arm is provided on eachblade and is preferably a part formed separate from the main portion ofthe blade, in which case it has a base fixed to the main portion lof theblade, as by welding or riveting, and has an inwardly projecting por-States Patent ICC tion, the terminal end of which enters between theplates of the holder. The several arms of the blades enter between theopposed anges of the holder and the projecting portions of the arms havetheir edges turned or deilected to form stiifening parts, and thesestiffening parts continue from the bases of the blades into the notchesprovided in the holder. The projecting portions of the arms not onlyenter between the spaced anges of the holder, but continue inward fromthe flanges toward the center of the holder, and suitable releasablefasteners are provided, securing the arms in the desired position in theholder. In practice screw fasteners such as bolts preferably serve toretain the arms engaged in the holder.

The various objects and features of my invention will be fullyunderstood from the following detailed description lof a typical,preferred form and application of the invention, throughout whichdescription reference is made to the accompanying drawings, in which:

Fig. l is a front elevation of a fan embodying the present invention,showing the several parts fully assembled so that the fan is completeand in Working condition. Fig. 2 is a View similar to Fig. l, showingthe parts exploded or separated, so that the arms of the blades areseparated from the holder on the hub. Fig. 3 is an en- Iarged,longitudinal sectional View of the structure taken as indicated by line3 3 on Fig. l. Fig. 4 is a transverse section taken as indicated by line4-4 lon Fig. 3. Fig. 5 is a perspective view of the hub showing thecentral portion of the holder in place thereon ready to be secured. Fig.6 is a view similar to Fig. 5, showing the holder secured on the hub,and Fig. 7 is a reduced sectional view taken as indicated by line 7-7 onFig. 4.

The construction provided by the present invention involves, generally,a hub A, means B for locking the hub on a shaft S or the like, a holderC mounted on or carried by the hub, blades D and mounting means Ereleasably mounting the blades on the hub A through or by means of theholder C.

The hub A is an elongate tubular element and has a central longitudinalopening 10 that is round or in the form -of a bore designed to receive ashaft S, yor the like. The means B provided for locking the hub on theshaft S may be any suitable means. In the drawings I have illustratedthe means B as involving set screws 11 carried in threadedr openings 12provided in the hub, the screws being operable from the exterior of thehub and being engageable with the shaft for setting the hub againstdisplacement from the shaft.

In accordance with the invention the hub has a holder retaining meansprovided thereon or combined therewith. In the preferred form of theinvention the hub has a portion 2Q of reduced diameter at one endforming a part von which the holder is held. The part 20 is smaller inoutside diameter than the adjoining portion of the hub, so there is ashoulder 21 against which the holder is engaged. The shoulder 21 ispreferably iiat and in a plane normal to the longitudinal axis of thehub. The portion of reduced diameter is substantially longer than isnecessary to hold the hub and a counterbore 22 is provided in theprojecting portion from its outer or terminal end, establishing theprojection with a thin projecting lip 23. As the hub is initially formedthe projecting portion 20, with its lip 23, has its exterior turned sothat it is uniform in diameter throughout the length of the projectionand is such as to slidably receive the holder.

The holder C, which is an assembly of parts as will be hereinafterdescribed, is engaged on the projecting portion 20 to abut the shoulder21, and when this is in place the lip 23 is deformed, for instance,pressed to project outwardly and into engagement with the end of the hubopposite to that engaging the shoulder 21, as clearly shown in Fig. 3 ofthe drawings. Through this construction the holder retaining means,which is provided on or which is a part of the hub, serves toVpositively and dependably retain the holder C on the projecting endportion of the hub with the holder in a plane normal to the longitudinalaxis'ofthehub.y 'Y Y,

The holder C provided by thepresent invention is formed by an assemblyof three parts, namely, two like plates 3) and a spacer 31 between theplates. The plates -30 are preferably at disc-shaped elements that arealike and which are formed of sheet metal. In the preferred form of theinvention each plate has a central opening 32 slidably receiving theprojecting portion on the end of the hub and in the form illustratedtheperiphery33 of the plate is curved concentric with the opening 32. Aplurality of notches 34 of substantial depth enters each plate from itsperiphery 33 dividing the plate into a plurality of circumferentiallyYspaced ange-like parts 36, In practice the number of notches 34 andconsequently the number of flanges 36 may be varied, it being preferred,ordinarily, to provide notches so that each plate has the same number ofanges as there are blades involved in the structure. In the caseillustrated the fan illustrated has four blades and consequently thereare four notches 34 providing four like flanges 36. v

In accordance with the present invention the spacer 31 is providedbetween the plates 30 and is preferably confined to the central portionof the holder, that is, to that portion of the holder which is engagedwith the hub. In the case illustrated the spacer 31 is in the form of asimple, annular plate or washer with a central opening corresponding insize with the openings 32 provided through the plates, and the washer isof limited extent radially, or in outside diameter, so that the plateshave annular portions projecting outward beyond the spacer and on whichthe anges 36 occur or are provided, as shown throughout the drawings. Inaccordance with the invention the several parts of the holder justdescribed, namely, the plates and the spacer, are arranged together orassembled as a gaged by the lip 23 has one or more recesses 38 providedin the wail of the opening 32 and the portion of the lip 23 formed toretain the holder on the hub is indented or shaped to project into oneor more of the recesses. In Athe case illustrated in the drawings thereare four recesses 33 and the lip 23 is indented at the four points 39shown in Fig. 6, with the result that the holder is effectively lockedon the hub against rotation relative thereto.

The blades D are preferably alike and the desired number of blades isprovided about hub A and is held by the holder C through the mountingmeans E. Each blade D involves aV main portion 40 formed of sheet metal,or the like, and so far as the present invention is concerned the mainportion 4t) may be of any suitable size, shape, or formation. In theparticular case illustrated the main portion 40 is substantially roundin shape and the edge portion 4i that faces inwardly or toward the hubis made somewhat concave, as shown in Figs. 1 and 2 of the drawings. Itwill be readily understood that in practice the high portion 4t? may beshaped or formed so that it is other than fiat and so that it has thedesired air handling action, and furthermore, if desired, it can beprovided with various features such as stiffening ribs 42 and the like.

The mounting means E provided for or in connection with each bladeserves to secure the blade to the holder C and, in accordance with thepresent invention, it involves an element that I Will term an arm 50,which arm has a base portion 51 fixed to the main portion 40 of theblade and a projecting portion 52 that projects radially Vinward fromthe main portion 4G of the blade, and has a. flat terminal end portion55 engaged byy thev holder C. `In the 'preferred construction the baseportion of the arm is substantially at or is formed to seat against oneside of the main portion 40 of the blade, and it is of substantial sizeor extent so that there is an adequate beating engagement between theportion 40 of the blade and the base of the arm. In the case illustratedthe base of the arm is permanently and rigidly fixed to the main portion40 of the blade, as by rivets .60. With the construction that I haveprovided the middle or central portion of the arm that occurs betweenthe flat terminal end 55 and the base portion 51 may be twisted orshaped so that the main portion 40 of the blade is supported relative tothe plane in which the holder occurs at any suitable angle, ascircumstances may require. The twisted or deflected central portion ofthe arm can, in practice, be shaped so that the fan has a substantialpitch or a slight pitch, as may be desired.

In accordance with the present invention the longitudinal edge portions65 of theprojecting. portions 52 ofV the arms are bent or turnedsomewhat from the planes of the arm portions to which they are joined,and as a result they form stitening elements that continue from the baseportion of the arm to the inner terminal end portion 55. In practice thestiifening flanges `or edge portions 65 of the arms materially stiienthe sheet metal arm members and v serve to effectively maintain the armsagainst bending or llexure.

In accordance with the present invention the iiat termiw nal end portion55 of the several arms project between the opposed anges 36 of theholder and these parts of the arms continue inwardly from the flanges 36to the spacer 31 or to points close to the spacer. The manner in whichthe flat terminal end portions 55 or the arms 'enter between the platesof the holder is clearly illustrated in Figs. 3 and 4 of the drawings.Where the parts are proportioned as shown in the ydrawings the innercorners of the arm portions 55 are bevelled or cut away as shown in Fig.4, so that these portions of the arms may be entered between the platesof the holder in the desired manner and without interferring with eachother, as would be the case if they were not bevelled or dressed away. Y

In accordance with the present invention the projecting portions 52 ofthe arms are wider than the anges 36 lof the holder in a directioncircumferentially of the holder, with the result that the reinforcing orstitfening edge portions or anges 65 of the arms are clear of theflanges 36 and extend inwardly into the notches 34 provided in theholder, as clearly illustrated in Fig. 4 of the drawings. By thus-notching the hollder so that the stiffening ribs or iianges of the armsenter well into the holder, the flanges between which the arms are held,in effect overlap the reinforced portions of the arms, with the resultthat there is no flexibility or weakness in the structure where the armsconnect to or are held by the holder.

The mounting means further includes releasable fasteners preferablyscrew fasteners such as bolts that retain the tlat terminal end portions55 of the arms engaged between the plates of the holder in the mannerillustrated in Figs. 3, 4 and 7 of the drawings. When bolt typefasteners are employed, as shown in the drawings, registering holes 76are provided in the arm portions 55 and the flanges 36 of the holder,and the desired bolts are passed through these registering openings. Itwill be apparent that in practice any desired number of bolts can beemployed in connection with or to hold each yof the arms, a typical boltarrangement being shown throughoutY the drawings.

With the construction provided by the present invention the hub 50, withthe holder C permanently fixed thereon, can be provided and a suitablenumber -of blades D, with arms 50 thereon, can be provided. These partscan be packed in a limited space, the blades being superimposed andnested together and the `structure can be stored, transported, andotherwise handled in this packed or knocked down position. When the fanis desired for use the at terminal end portions 55,of the armsoccunringon .the

blades are inserted between the anges 36 yof the holder to projectinward beyond the anges, as shown in Fig. 4, and when in workingposition the fasteners `or bolt-s 75 Iare applied. When the bolts 75 aremade fast or tight the anges 36 of the two plates at each arm can beflexed or clamped tightly toward each other to solidly grip the arm andbecause of the presence of the notches 34 the flanges 36 at the arms aresomewhat independent of each other, so that each arm can be effectivelyand securely gripped by suitable tightening of the fasteners relatedthereto. The terminal end portions 55 of the arms being extended inwardfrom the anges 36 have substantial engagement with and between theplates of the holder, -so that the arms are effectively and dependablymaintained in the ldesired relationship to the holder. From theforegoing description it will be apparent that the holder, in turn, iseffectively and dependably secured on the hub, yand with the means Dillustrated the hub can be suitably fixed on a shaft S, or the like,provided for operating the fan.

Having described only a typical preferred form and application of myinvention, I :do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to myself any variationsor modifications that may appear to those skilled in the art and fallwithin the scope of the following claims.

Having described my invention, I claim:

1. A fan including, an elongate hub with a central longitudinal shaftopening therein, a holder permanently fixed on the hub and including, apair of like longitudinally spaced disc-shaped plates withcircumferentially spaced radially outwardly opening notches in theperipheries thereof, blades, elongate arms on the blades extendinginwardly therefrom and between the plates, and releasable screwfasteners securing the arms in tight clamped engagement between theplates, the arms having base portions fixed to the blades, portionsprojecting from the base portions toward the hub and flat terminal endportions between the plates, the arms having stiiening parts at theedges thereof and projecting laterally therefrom and entering thenotches in the plates and adapted to prevent shifting of the bladesrelative to the hub.

2. A fan including an elongate hub with a central longitudinal shaftopening therein, a holder on the hub, and blades with arms releasablyheld engaged with the holder, the holder comprising three parts, onebeing an annular spacer and the other two being like apertured platesheld apart by the spacer and having radially projecting parts betweenwhich the arms are entered, the hub having a shoulder at one end, acylindrical portion of reduced diameter projecting longitudinally fromthe shoulder to slidably engage and carry the plates and spacer, and aradially outwardly projecting lip on the outer terminal end of the saidcylindrical portion and permanently en- 6 gaged with the holder andholding it tight against the shoulder, the plates having recessestherein adjacent the said cylindrical portion of the hub and the liphaving a longitudinally offset part engaged in a recess in one of theplates.

3. A fan including, an elongate cylindrical hub with a centrallongitudinal shaft opening and having a shoulder at one end, a portionof reduced diameter projecting from the shoulder and a radiallyoutwardly projecting lip on said portion and spaced from the shoulder, aholder including two like apertured disc-shaped plates and an annularspacer between the plates, the holder being lslidably engaged on saidportion of the hub between the said shoulder and lip and permanentlyheld against the shoulder by the lip, the plates havingcircumferentially spaced notches in the peripheries thereof establishingcircumferentially spaced anges at the periphery of the plates, blades,arms on the blades projecting therefrom toward the hub and having at endportions between flanges of the plates, and screw fasteners releasablysecuring the end portions of the aims in tight clamped engagementbetween the flanges, the arms having turned and offset edge projectionsextending longitudinally thereof and into the notches.

4. A fan including, an elongate cylindrical hub with a centrallongitudinal shaft opening and having a shoulder at one end, a portionof reduced diameter projecting longitudinally from the shoulder and aradially outwardly projecting lip on said portion and spaced from theshoulder, a holder including two like disc-shaped plates with centralopenings and an annular spacer between the plates, the holder beingslidably engaged on said portion of the hub and permanently held againstthe shoulder by the lip, the plates having circumferentially spacednotches in the peripheries thereof establishing circumferentially spacedflanges at the periphery of the plates, blades, arms on the bladesprojecting therefrom toward the hub and having at end portions betweenanges of the plates and extending between the plates inward of theflanges, and screw fasteners extending through the plates and throughthe said end portions of the arms and releasably securing the endportions of the arms in tight clamped engagement between the flanges.

References Cited in the le of this patent UNITED STATES PATENTS2,041,555 Lee May 19, 1936 2,317,502 Upson Apr. 27, 1943 2,395,193 PlaceFeb. 19, 1946 2,579,119 McDerment Dec. 18, 1951 2,581,872 Morrison Jan.8, 1952 2,585,265 Moeller Feb.V 12, 1952 2,681,708 Mix June 22, 1954

